Optimisation of ICPMS collision/reaction cell conditions for the simultaneous removal of argon based interferences of arsenic and selenium in water samples

The optimisation of ICPMS collision/reaction cell conditions for the simultaneous analysis of arsenic and selenium is described. A mixture of 3.8 mL min−1 of H2 and 0.5 mL min−1 of He was found to be suitable for the removal of both ArAr+ and ArCl+ interferences. Detection limits down to 30 ng (element) L−1 in total analysis, and between 81 and 230 ng (element) L−1 in speciation analysis were achieved in chloride matrix (1 g L−1 NaCl). After validation, the method was applied to commercially available mineral waters.